Duplicate engine



No. 748,975. PATENTED JAN. 5, 1904.

J. W. NEIL. DUPLICATE ENGINE.

APPLICATION FILED APR. 5. 1902.

N0 MODEL.

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UNITED STATES Patented January 5, 1904.

PATENT OFFICE.

DUPLICATE ENGINE.

SEECIFICATION forming part of Letters Patent No. 748,975, dated January 5, 1904.

Application filed April 5, 1902. $erial No. 101.466. N0 model-.

To aZZ whom it may concern:

Be it known that 1, JOHN W. NEIL, a citizen of the United States of America, and a resident of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Dupli cate Engines, of which the following is a specification.

The object of my invention is a duplicate engine the admission and exhaust of whose cylinders are controlled by a single valve.

In the accompanying drawings, in which like parts are indicated by similar reference letters, Figure 1 is a perspective View of a duplicate engine embodying my invention, the valve and its casing being shown in section and the pistons in the cylinders and the channels leading from the Valve-casing being shown in dotted lines. sectional View of the same, taken upon line i; 1; of Fig. 1. Fig. 3 is a horizontal sectional view taken upon irregular line 00 a; of Fig. 2, showing the posit-ion of the ports and channels.

Referring to the parts, cylinders A A are situated side by side, having within them reciprocating pistons a, and a, which in their movements are one-half a stroke apartthat is, when one of them is at the forward end of its cylinder the other is at the rear end of its cylinderall of which is similar to duplicate engines now in use, and therefore need not be described more specifically.

Situated between cylinders A and A and preferably cast integral with them is a cylinder valve-casing B, which contains a primary cylindrical chamber 1) and a secondary cylindrical chamber b, the latter being of a smaller diameter than and in alinement with the former.

Centrally located in the bottom of chamber 1) is an exhaust-port 19 which leads into exhaust-channel b and upon each side of port I) and at equal distances therefrom are ports b 19 From port b a channel a leads to the rear end of cylinder A and a channel a leads to the forward end of cylinder A. From port 13 a channel a leads to the forward end of cylinder A and achannel a leads to the rear end of cylinder A.

Within chamber 1) are three pistons C C Fig. 2 is a transverse C secured at equal distances apart upon a piston-rod c, which extends into chamber b and there receives a piston C When they are in the position shown in Fig. 1, the rear end of cylinder A and the forward end of cylinderA are in communication with the live steam which enters chamber 19 through opening I), and the forward end of cylinder A and the rear end of cylinder A are in communication with the exhaust, and pistons a and a are moving in the direction of the arrows marked on their rods. The means for moving the valve to reverse these conditions are as follows; Within rod 0 are two channels 0 and 0 the former of which runs from a point between pistons C and C into chamber 6 upon the right-hand side of disk 0 and the latter of which runs from a point between pistons C and C to the left-hand face of disk O A channel 01, runs from the forward end of cylinder A at a distance from the end thereof slightly greater than the thickness of piston a to the forward end of chamber 1), and a channel a runs from a point a similar distance from the forward end of cylinder A to the rear end of chamber b. While the parts are in the position of Fig. 1 the left-hand faces of pistons C and C and the right-hand faces of pistons C and C beingin communication with the exhaust have no pressure on them, and the right-hand faces'of C and C and the left-hand faces of C and C being in communication with the live steam the pressure on C counterbalances that on C, and C being larger in area than C the valve is held at the left-hand limit of its path. However, when piston a passes the point where channel a enters cylinder A the left-hand face of piston C is placed in communication with the live steam, so that the pressure upon it counterbalances that on piston C and allows the pressure on piston C to carry the valve to the right-hand limit of its travel, placing the forward end of cylinder A and the rear end of cylinder A in communication with the live steam and the rear end of cylinder A and the forward end of cylinderA in communication with the exhaust and reversing the movement of the pistons. When piston a passes the point where channel a enters cylinder A, the

valve is moved to the left-hand end of its travel in a manner similar to that aforedescribed.

What I claim is- 1. An engine having two cylinders, a piston within each cylinder, a valve-casing, a reciprocating valve within the casing, channels leading from the valve-casing into both ends of the cylinders, secondary channels leading from one of the cylinders into the valve-casing to convey steam thereto to reciprocate the valve to put the ends of the cylinders alternately, one in communication with the live steam and the other with the exhaust, and means for regulating the secondary channels by the piston of the cylinderfrom which they lead, substantially as shown and described.

2. A duplicate engine having two pistoncylinders, and having a valve-casing situated between its cylinders with an exhaust-port and a port upon one side and upon the opposite side of the exhaust-port, channels connecting each of the latter ports one with the forward end of one cylinder and the rear end of the other cylinder and connecting the other port with the rear end of the first cylinder and with the forward end of the latter cylinder, a. valve in the casing for placing said ports alternately in communication with the exhaust and with the live steam, and means for reciprocating the valve, substantially as shown and described.

3. In a duplicate engine having two cylinders with a piston within each cylinder the combination of a valve-casing situated between the cylinders of the engine, and having an exhaust-port with two ports one on each side thereof, pistons upon a common pistonrod within the valve-casing for putting the two ports alternatelyin communication with the exhaust, channels connecting one of the two ports with the forward end of one of the cylinders and with the rear end of the other cylinder and connecting the other of said ports with the rear end of the former and. with the forward end of the latter cylinders, and channels leading from the same ends of the two cylinders at points thereof distant from the ends greater than the thickness of the engine-pistons and one leading to the forward and the other to the rear end of the valve-casing to shift the balance of pressure and reciprocate the valve, substantially as shown and described.

JOHN W. NEIL.

Witnesses:

W. F. MURRAY, EMMA LYFORD. 

